Irrevocably Allied
by Taliya
Summary: Despite learning that they worked towards the same goal, he loathed him and wanted him dead. But did he really, knowing that working together was one of their best shots at bringing the Organization down? Major spoilers for the Scarlet arc. Rated for language.


Detective Conan and Magic Kaito characters, settings, and ideas do not belong to me but to Aoyama Gōshō.

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Irrevocably Allied

By Taliya

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Furuya Rei sat on an out-of-the-way bench in Beika Park, soaking in the late afternoon warmth of the sun. Today was unseasonably mild for late October, and many others, like himself, were out and about to take advantage of the glorious weather. Families were out with parents indulgently allowing their children to chase each other in the playgrounds, burning off excess energy from being contained indoors the past two days due to overall gloomy cloudiness and mist.

Inhaling deeply, he allowed autumn to flood his senses: the rustle of the fallen and falling leaves in the wind, the scent of earth mixed with the crisp tang of winter on its way, the explosion of colors that ranged from the stately greens of the cedars to the riotous yellows, oranges, and reds of the maples, the gentle warmth of the sun's rays on his face—and for one instant he wished he could live in this moment of unspoiled, simple _existence_ forever.

Rei knew that such a thing was actually not possible, that he was hopelessly and eternally mired in tendrils of tarry black, but he had chosen this life for a purpose and he would not falter. He had once had a companion to commiserate with regarding their similar situations, but he had been killed long ago, revealed as an undercover triple agent. The loss still ached in his chest as though his heart had been torn out, leaving a ragged wound that had never healed.

He shook his head, unwilling to allow such gloomy thoughts to dampen the beauty of this flawless fall afternoon. Standing up from the bench, he checked his watch before deciding to search for an early dinner. He absently stepped out onto the gravel pathway only recoil instantly as he encountered resistance along with a simultaneous yelp in the neighborhood of his knees.

Snapping back to the present, his eyes cut down to his feet where a grimacing Edogawa Conan gingerly rubbed his backside where he had fallen.

"Conan-kun!" he exclaimed as he knelt, his words echoed by another in near perfect stereo. He glanced up to find none other than Okiya Subaru before him, also ready to help the fallen youth. Between the two of them they levered the boy to his feet, and the young bespectacled detective dusted himself off.

"I'm sorry," he apologized as he mentally slid the mask of Amuro Touru's sociable personality on, "I wasn't paying attention to where I was going. You're not hurt, are you, Conan-kun?"

"Nm," Conan hummed with a shake of his head, smiling at the blond. "I'm good." The elementary student grinned up at him. "I wasn't paying attention either."

"And that would be my fault," the graduate student murmured, inserting himself into the conversation. "I was trying to explain what my thesis topic was about without getting into too much detail, since he asked." He pushed his glasses further up onto his nose with a thoughtless flick of his fingers—habit. "Normally I would say the division of fault is fifty-fifty, but in this case it would be more equal split into thirds, I suppose."

The sentence slammed him in the gut with the power of a sledgehammer. The phrasing, the diction—there had only ever been one man to use that sort of terminology in his admittedly long list of acquaintances, and it cemented the deduction in his mind that had, somehow, been _conclusively_ proven wrong just one week prior. _How is it possible that Akai Shuuichi stands before me disguised as Okiya Subaru when not seven days ago, they had been two separate people?_ His confusion manifested itself on his face in between the space of one breath and the next before his expression cleared, swept beneath the veneer of genial, mild-mannered Amuro Touru. It was something he would have to think about later, once he extricated himself from his current situation. "Okiya-san," he greeted, sending the other man a small smile, which the graduate student returned with a murmured, "Amuro-san," of his own.

"What brings you out here today, Amuro-no-nii-chan?" Conan chirped, cerulean eyes gazing up at him expectantly.

Pasting on the barista's amiable smile, Touru replied, "I had the day off and no cases to solve today, so I thought I'd come out and enjoy the weather." His cobalt-colored eyes lifted towards the sky. "It was just too beautiful to stay indoors." He returned his eyes to the shorter of his two companions. "And you? Are your friends busy today?"

Conan shrugged. "They went to watch the Gomera second remake series' rerun marathon at the theater. I wasn't too interested in sitting through six movies, so I begged off."

"Personally I don't see why Conan-kun shouldn't skip grades and enroll in high school," Okiya commented, "Since he is already so far ahead of his peers." There was the slightest smirk about the man's lips, as though he were internally laughing at some private joke. And from the way Conan grimaced in barely-hidden panic, it was abundantly clear that the grade-school boy knew exactly what Okiya was referring to—which only served to further rouse both his suspicion and curiosity.

"Oh?" he inquired, determined to chase this latest topic of intrigue. "What makes you say that?"

Okiya was cut off by Conan's boisterous—and obviously fake—laughter. "Subaru-san is exaggerating!" he exclaimed, for whatever reason turning up the child-wattage to near-painful levels of… cuteness. As it was, the barista barely managed to refrain from shuddering. "I just know a lot from watching the television," Conan chirruped in explanation. He froze as his mobile rang, and with careless ease he answered the phone. "Ran-nee-chan?" he asked after a moment of listening to his caller. Both Amuro and Okiya patiently waited while young Edogawa conversed with his guardian. "Aw, do I _have_ to?" he whined, visibly pouting despite the fact that Mouri Ran was not there to see it. "But…! I… Okay, _fine_ …" he capitulated with a deep sigh. "I'll see you soon." He flipped the red device shut and stuffed it in his pocket. "Ran-nee-chan says I have to go home. She wants to do some shopping and insists that I come along." Conan wrinkled his face to show his distaste for the activity, and both of the older males chuckled knowingly.

"Do you need me to walk you back?" Okiya asked, and Conan shook his head.

"I'll be fine," he replied. "Bye, Subaru-san, Amuro-no-nii-chan!" he called as he scampered out of the park towards the detective agency, leaving the graduate student and the barista alone. The atmosphere between the two cooled precipitously.

"Give me one reason why I shouldn't call you in," he hissed quietly, Amuro Touru's affable façade sublimating to reveal a frosty mask of barely-contained hatred.

"Whatever do you mean? Have I done something to you?" the bespectacled man queried, tilting his head in puzzlement.

Bourbon roughly fisted the lapels of Okiya's jacket and yanked him so that they were practically nose-to-nose. "Don't _fuck_ with me, Akai," he snarled, navy eyes narrowing darkly.

Okiya fully opened his squinted eyes, revealing steel-grey irises that Bourbon utterly _despised_. "Don't get distracted by what's in front of you and pursue the wrong prey, Furuya," Akai Shuuichi warned, repeating his words from a week ago. His voice, however, still remained solidly Okiya Subaru's, and somewhere in the back of his mind the assassin felt savage satisfaction at having his deductions proven correct. Now if only…

His fists tightened in the cloths of Akai's knit sweater and cotton button up as he debated whether or not to off the man while he still had him in his grasp. _Damn_ the witnesses, Gin would be pleased to see the FBI agent gone for good. He would be praised, elevated in status, one step closer to eliminating Ano Kata…

" _Don't_ ," the undercover agent repeated, and Bourbon felt the looming ghost of Rye rise to the forefront of the other man's persona.

The presence of someone as threatening as Rye had Bourbon raising his metaphorical hackles, and he barely resisted the urge to draw his gun in reflexive self-defense. _Goddammit,_ he swore, clenching his teeth hard enough to make them squeak, _Why does this man always manage to get to me?!_ Then his mind processed the single word command, along with its many possible implications and he ground out, " _Why?_ " Bourbon was not quite sure what exactly he was asking about. There were a host of possibilities: his desire to complete his mission, his desire for vengeance, his desire to gain Ano Kata's trust…

Akai sighed, the sound weary and aged, and Rye's ominous presence receded and dissipated. "I don't want you to be a casualty too."

 _That_ brought Bourbon up short, and he blinked, frowning. Slowly, and with great reluctance, he released the other man, watching stonily as Akai adjusted his collar and submerged himself in Okiya Subaru's milder demeanor. "Explain," he demanded tersely, struggling to pull the barista's pleasant façade back on. He only managed it partway, leaving Furuya Rei bare to the world, and at the moment he could have cared less.

With grey eyes once again hidden, the graduate student began to explicate. "As I had been explaining to Conan-kun, the structural integrity of a construct begins at its foundation. Without a solid foundation, anything built upon that foundation would inevitably crumble." He began to pace down the pathway in the direction he and Conan had originally been headed, and Rei grudgingly, warily followed. "In order to build that foundation, there has to be uniformity, a cohesiveness that will render it strong. In the case of a katana, the foundation is the carbon steel used to forge the blade. There has to be the perfect balance of carbon and iron in the composition in order to make the blade both durable and strong. Too much carbon, and the blade will break; too much iron and the edge will chip. Both need to be in perfect harmony in order to forge a blade that will serve its user well.

"The steel is then folded and welded multiple times. Different grades of steel are used for different parts of the katana: low-carbon hocho-tetsu for the core of the blade, while high carbon tamahagane and nabe-gane are alternately folded to produce the edge. To aid in creating purity of material, clay is used to draw out impurities in the steel. The blade is then differentially heat-treated to create the greatest combination of pliability and hardness. Katana forging in a nutshell. Still follow?" the undercover agent asked. By this point, Okiya had led Furuya to a secluded corner of the park. The sound of children's laughter filtered faintly through the rustling, yellowed branches of willow, and a small stream tinkled cheerily nearby. There was no one in sight.

"What's your point?" the Public Security Bureau agent grunted, eying the man cautiously.

Okiya regarded the triple agent gravely before he once again opened those abhorrent silver eyes as he reached up and adjusted the collar of his shirt. Akai's gaze pierced him with their intensity and sincerity. He cleared his throat, then spoke in his true voice. "You and I are but the raw materials needed to forge a weapon, and if we work in tandem we could easily bring down the Organization, relatively speaking. Work with me, so that we can end this war—so that we can sooner retire to lick our wounds and lay our ghosts to rest."

At the scowl that darkened Rei's expression, the FBI agent closed his eyes and sighed wearily. "I'm not going to apologize for what I did," he murmured. "But for what it's worth, I am sorry." There was genuine remorse in his voice, but there was resolution, too.

Rei glanced away from the man, hating the fact that he could sympathize, that he knew all too well what it was like to be in his situation. Had done it once before. His hands curled into quivering fists as he contemplated what to do with this new information.

"So?" Okiya Subaru was back complete with voice, mild and nonjudgmental. "What do you plan to do, now that you know?"

The triple agent glared at the disguised man with unconcealed dislike. "Nothing, for now," he rumbled. "I will not out you to them, since what you said is nothing but the truth. However," he warned, eyes flashing dangerously. "Get in my way and I will not hesitate to kill you."

The dark smirk that twisted the graduate student's lips was decidedly out of place, considering his nature. "Copy that."

Unwilling to spend any more time in the FBI agent's presence than necessary, Rei twisted on his heel and stalked off, his mood soured by the encounter. He did manage to pull himself together enough to paste Touru's pleasant smile on his face as he passed by people lingering in the park. Rei made it back to his apartment without incident, throwing himself into the lone armchair of his living room, his amiable grin melting into a thunderous scowl. His fingers tapped the ends of the armrests in agitation. He itched to do something, anything, to smother this restlessness within him.

 _"Fuck,"_ he snarled viciously, standing up to pace in circles around his small living room area. _Damn that man,_ he internally growled. _Manipulating me to his side! I know what he did just now, and I allowed it._ There was too much logic involved; Rei knew without a doubt that it was in their best interests to work together to achieve the goal of bringing the Organization down. It did not mean, however, that he had to like it. _A fucking thorn in my side, even when I thought he was dead!_ He prowled about his apartment as he sorted his thoughts out, struggling to set aside his animosity for the greater good.

But then there was the question of the undercover FBI agent revealing himself. Had it been inadvertent or intentional? Considering the trouble he went through to prove he was still alive while not blowing his cover meant that it _had_ to have been unintended.

His knee-jerk reaction had been to get Gin on the phone to inform him of his latest discovery, but Akai had managed to talk him out of that particular plan of action. So question of the day—or evening, if one got technical—had become: _Now what?_

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 _Damn!_ Okiya Subaru's normally hospitable expression tightened into one of distinct displeasure, his brows drawn into a frown and his lips pursed tightly as he locked the front door behind him and fully opened his eyes. _I hadn't meant to slip like that!_ With agitation in his steps, he strode towards the Kudou library, where he had set up his base of operations. His laptop rested on the single desk within the circular room, and he settled into the leather swivel chair with a sigh as the frame creaked under his weight. He leaned back, his fingers steepled against his lips as he contemplated his next move.

Bourbon now knew who he was, underneath the disguise of Okiya Subaru. He had made it abundantly clear upon the Bureau agent's realization that they were and always had been working toward the same goal: the destruction of the Black Organization. Shuuichi scowled. He was well aware of Furuya's immense dislike of him, particularly after he had gone through the trouble of trying to smoke him out. Thankfully the boy—seven-year-old Edogawa Conan, who Shuuichi knew to be a de-aged seventeen-year-old Kudou Shinichi—had realized early enough that Bourbon had begun investigating his faked death to implement a rather ingenious plan to maintain his cover—

—only for him to blow it with a single phrase.

 _"Fuck,"_ he swore fervently, and he fleetingly thought with wry humor how odd it sounded for Okiya Subaru to swear. He unbuttoned the collar of his shirt roughly in self-directed fury before pressing the button that would deactivate the voice-changing invention of Agasa's that he wore. He considered pouring himself a snifter of the bourbon whiskey that sat in its bottle off to the side of his laptop before dismissing the idea. He was angry and upset, and mixing alcohol would do him no favors. Right now he needed to calm down and determine the best method to do damage control.

And nothing helped him think more than a shower and soak in the furo. He padded to the bathroom, locking the door before stripping himself of both clothes and disguise and washing himself methodically. After a final rinse, he climbed into the tub, leaning back and staring at the ceiling as ideas buzzed through his head, swiftly judged and discarded one after another. Eventually he decided the best course of action would be to utilize the fact that they now knew who the other's allegiances truly belonged to pool their combined knowledge resources together to form a plan of attack. Shuuichi knew that pulling in Edogawa—Kudou—was a necessity, but considering the young detective had yet to reveal himself—to his knowledge, at least—to Furuya meant that the boy did not fully trust the Security Bureau agent. Though to be fair, Shuuichi knew he himself was never meant to have found out either.

Shuuichi recalled the first time he had truly worked with young Edogawa Conan. While initially he had wondered why a primary-school child constantly seemed to tag alongside Jodie, it was only upon Kir's capture that he truly realized the incredible mind housed inside that tiny body. The plan Edogawa had come up with detailing Kir's return to the Black Organization and her need to prove she had not been compromised was nothing short of genius. That a seven-year-old boy could strategize that far out… he already had the makings of a detective worthy of being Sherlock Holmes' successor.

It had been somewhat disturbing to find that mind in a child so young, and yet when he discovered that Edogawa Conan was really Kudou Shinichi, who was hiding from the very same Organization, it allowed him to breathe a little easier in relief. It had not really sat all that well with him, knowing that a child barely a quarter of his age could outsmart some of the cleverest minds both the criminal and law enforcement worlds had to offer.

So—what now? He had already established that joining forces with Furuya would work best in their favor, though he had no plans of interfering with any of Bourbon's designs. A truce was a given, but to be honest it was better that they simply continue their own paths, using their own methods to draw out the Organization. There was no way to truly plan for the future unless he had Kudou's help, and thus far Shuuichi had decided that his current situation did not warrant the detective's insight just yet.

He pulled himself out of the bath and dried off, reapplying his disguise with the ease of many hours of practice. Heading to the kitchen, he pulled out a pot of stew he had made yesterday and set it on the stove to reheat. The rice in the rice cooker had been set on warm, so there was no need to make more rice tonight. As he waited for the stew to heat, he grabbed his laptop from the library, surfing on the internet for news while he checked his inbox for new emails. Memos from James and Jodie were quickly read, while advertisements were junked and deleted.

He spooned a bowl for himself after the pot had warmed the contents thoroughly, adding a side of rice to his dish. He set the plate down and was just about to dig in when his front doorbell rang. Frowning, he set his spoon down and made his way to the genkan, stifling his surprise upon finding Furuya Rei on his doorstep.

"May I help you?" Okiya Subaru asked, voice pleasant and seemingly carefree.

Amuro Touru's smile was returned. "May I step in for a moment? I have something I would like to discuss with you regarding a tab at Café Poirot," the barista answered.

The graduate student frowned but nodded, stepping aside. "I have not yet visited Café Poirot," he murmured, offering house slippers to the blond before leading him to the same sitting room Okiya Subaru had hosted Bourbon once before. They stood before the opposing sofas, Amuro declining the offer for a drink or the offer to sit.

"I'll be brief," Furuya said, dropping the barista's amiable demeanor, and Shuuichi allowed Okiya's smile to dim slightly. "I won't turn you in because despite my personal feelings I believe cooperation between us will be necessary in the future. That being said, pooling our knowledge and resources would be… advisable."

Shuuichi could clearly see how much setting down the metaphorical knife chafed the man before him and felt it only fair that he reciprocate—though he no longer carried that same type of anger and hurt. He adjusted his collar as he opened his eyes fully, discreetly disengaging the voice changer. "I'm glad," he finally said after considering what he wanted to portray. "I was hoping you'd come to the same conclusion I did." His eyes took in the other man, watched the smoldering hatred barely veneered behind Furuya's dark blue eyes and he felt a pang of pity. "I will, of course, be amenable to an exchange of information. But beyond that, I cannot promise the cooperation of the FBI, though I can vouch for myself."

Furuya nodded curtly, once. "Fair enough. I'll see myself out." The Security Bureau undercover officer swiveled and marched himself out of the sitting room, his strides swift and tense.

Shuuichi caught up with him at the front door, where the blond had already gotten his shoes on. "Amuro-san," he said in Okiya's gentler tones. "I'll drop by every now and then to pay off that tab that I've racked up," he said as the barista opened the door.

Amuro smiled kindly back. "I'd appreciate that," he replied. His eyes flashed once before it was blanked, and he offered a quiet, "Good night, Okiya-san," before he retreated down the walkway and let himself out of the gate.

"Good night, Amuro-san," Okiya called back before he closed and locked the door. He allowed himself a moment to slump against the door before he straightened and made his way back to the kitchen and his now cold plate of rice and stew. As he microwaved his dinner, Shuuichi contemplated the way forward, noting the various ways he could incorporate his ornery new ally into the FBI's plans to take down the Black Organization.

There was much to be done.

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Author's Note: A shorter piece than my usual. I guess I wanted to try my hand at two characters I'd never done before but who I have come to adore—I started this before I wrote _Veils Between Worlds_ —though not quite on the same level as either Kaito or Shinichi. Those two are always going to be my first loves. I wanted to explore the complexities of their relationship and their history, and how it colors their interactions when they are not allowed to act freely all while knowing that the other knows who they truly are… if that made any sense whatsoever. At any rate, I hope I adequately captured a fraction of how their working and personal relationships with each other work, realistically speaking, though honestly I'm not entirely happy with the ending since I have no idea how it got away from me. I felt like they were thinking and talking in circles, but… I hope you enjoyed it.

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Completed: 22.11.2015


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